When you look at a genre such as RPG's, D&D was one of the first games to bring it to life. Over the years there have been others (Rifts, All the White Wolf games, etc) and really just about every type of imagination is represented now.
WoW basically took what D&D represents and put it into a game form that worked for people who are too damned lazy to let their imagination be used as it should be. This is due to societies lack of caring for the nurturing of the human mind and more their belief in the human condition of apathy and self-loathing; but that is an argument for another day.
In the end, WoW and D&D are similar, but very much different. If you and your friends enjoy letting your imagination dictate what you see and how you perceive it, then D&D or other RPG's are the way to go. If you and your friends have the creative insight of a gerbil, then WoW is the way to go as playing D&D for people with insights that poor is like having a newborn read War and Peace.